Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Psychedelic Geometric Background No Black
Source GDJ
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
Abstract Ellipses Background Grayscale
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
A seamless pattern the starting point for which was a 'light rays' rendering in Paint.net.
Source Firkin
This could be a hippy vintage wallpaper.
Source Tileable Patterns
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
A free seamless background texture that looks like a brown stone wall.
Source V. Hartikainen
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This metal background pattern resembles a metal plate with rivets. Solid rivets on a metal plate.
Source V. Hartikainen